[PATCH v6 2/4] docs/perf: Add documentation for the Amlogic G12 DDR PMU

[Jiucheng Xu]

On 2022/9/4 1:35, Chris Healy wrote:
> [ EXTERNAL EMAIL ]
>
> On Wed, Aug 31, 2022 at 7:45 PM Jiucheng Xu <jiucheng.xu at amlogic.com> wrote:
>> Add a user guide to show how to use DDR PMU to
>> monitor DDR bandwidth on Amlogic G12 SoC
>>
>> Signed-off-by: Jiucheng Xu <jiucheng.xu at amlogic.com>
>> Reported-by: kernel test robot <lkp at intel.com>
>> ---
>> Changes v6 -> v5:
>>    - No change
>>
>> Changes v5 -> v4:
>>    - Fix building warning
>>
>> Changes v3 -> v4:
>>    - No change
>>
>> Changes v2 -> v3:
>>    - Rename doc name from aml-ddr-pmu.rst to meson-ddr-pmu.rst
>>
>> Changes v1 -> v2:
>>    - Nothing was changed
>> ---
>>   Documentation/admin-guide/perf/index.rst      |  1 +
>>   .../admin-guide/perf/meson-ddr-pmu.rst        | 70 +++++++++++++++++++
>>   MAINTAINERS                                   |  1 +
>>   3 files changed, 72 insertions(+)
>>   create mode 100644 Documentation/admin-guide/perf/meson-ddr-pmu.rst
>>
>> diff --git a/Documentation/admin-guide/perf/index.rst b/Documentation/admin-guide/perf/index.rst
>> index 69b23f087c05..997a28e156c1 100644
>> --- a/Documentation/admin-guide/perf/index.rst
>> +++ b/Documentation/admin-guide/perf/index.rst
>> @@ -17,3 +17,4 @@ Performance monitor support
>>      xgene-pmu
>>      arm_dsu_pmu
>>      thunderx2-pmu
>> +   meson-ddr-pmu
>> diff --git a/Documentation/admin-guide/perf/meson-ddr-pmu.rst b/Documentation/admin-guide/perf/meson-ddr-pmu.rst
>> new file mode 100644
>> index 000000000000..28e9910940d0
>> --- /dev/null
>> +++ b/Documentation/admin-guide/perf/meson-ddr-pmu.rst
>> @@ -0,0 +1,70 @@
>> +.. SPDX-License-Identifier: GPL-2.0
>> +
>> +===========================================================
>> +Amlogic SoC DDR Bandwidth Performance Monitoring Unit (PMU)
>> +===========================================================
>> +
>> +There is a bandwidth monitor inside the DRAM contorller. The monitor include
> Fix spelling of word "controller" and add an s to the end of include
Oh, I will update it in next version.
>
>> +4 channels which can count the read/write request of accessing DRAM individually.
>> +It can be helpful to show if the performance bottleneck is on DDR bandwidth.
>> +
>> +Currently, this driver supports the following 5 Perf events:
>> +
>> ++ meson_ddr_bw/total_rw_bytes/
>> ++ meson_ddr_bw/chan_1_rw_bytes/
>> ++ meson_ddr_bw/chan_2_rw_bytes/
>> ++ meson_ddr_bw/chan_3_rw_bytes/
>> ++ meson_ddr_bw/chan_4_rw_bytes/
>> +
>> +meson_ddr_bw/chan_{1,2,3,4}_rw_bytes/ events are the channel related events.
>> +Each channel support using keywords as filter, which can let the channel
>> +to monitor the individual IP module in SoC.
>> +
>> +The following keywords are the filter:
>> +
>> ++ arm             - DDR access request from CPU
>> ++ vpu_read1       - DDR access request from OSD + VPP read
>> ++ gpu             - DDR access request from 3D GPU
>> ++ pcie            - DDR access request from PCIe controller
>> ++ hdcp            - DDR access request from HDCP controller
>> ++ hevc_front      - DDR access request from HEVC codec front end
>> ++ usb3_0          - DDR access request from USB3.0 controller
>> ++ hevc_back       - DDR access request from HEVC codec back end
>> ++ h265enc         - DDR access request from HEVC encoder
>> ++ vpu_read2       - DDR access request from DI read
>> ++ vpu_write1      - DDR access request from VDIN write
>> ++ vpu_write2      - DDR access request from di write
>> ++ vdec            - DDR access request from legacy codec video decoder
>> ++ hcodec          - DDR access request from H264 encoder
>> ++ ge2d            - DDR access request from ge2d
>> ++ spicc1          - DDR access request from SPI controller 1
>> ++ usb0            - DDR access request from USB2.0 controller 0
>> ++ dma             - DDR access request from system DMA controller 1
>> ++ arb0            - DDR access request from arb0
>> ++ sd_emmc_b       - DDR access request from SD eMMC b controller
>> ++ usb1            - DDR access request from USB2.0 controller 1
>> ++ audio           - DDR access request from Audio module
>> ++ sd_emmc_c       - DDR access request from SD eMMC c controller
>> ++ spicc2          - DDR access request from SPI controller 2
>> ++ ethernet        - DDR access request from Ethernet controller
>> +
>> +
>> +The following command is to show the total DDR bandwidth:
>> +
>> +  .. code-block:: bash
>> +
>> +      perf stat -a -e meson_ddr_bw/total_rw_bytes/ -I 1000 sleep 10
>> +
>> +This command will print the total DDR bandwidth per second.
>> +
>> +The following commands are to show how to use filter parameters:
>> +
>> +  .. code-block:: bash
>> +
>> +      perf stat -a -e meson_ddr_bw/chan_1_rw_bytes,arm=1/ -I 1000 sleep 10
>> +      perf stat -a -e meson_ddr_bw/chan_2_rw_bytes,gpu=1/ -I 1000 sleep 10
>> +      perf stat -a -e meson_ddr_bw/chan_3_rw_bytes,arm=1,gpu=1/ -I 1000 sleep 10
>> +
>> +The 1st command show how to use channel 1 to monitor the DDR bandwidth from ARM.
>> +The 2nd command show using channel 2 to get the DDR bandwidth of GPU.
>> +The 3rd command show using channel 3 to monitor the sum of ARM and GPU.
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index ac8a98dfbacc..8ee68e699e6d 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -1054,6 +1054,7 @@ AMLOGIC DDR PMU DRIVER
>>   M:     Jiucheng Xu <jiucheng.xu at amlogic.com>
>>   S:     Supported
>>   W:     http://www.amlogic.com
>> +F:     Documentation/admin-guide/perf/meson-ddr-pmu.rst
>>   F:     drivers/perf/amlogic/
>>   F:     include/soc/amlogic/
>>
>> --
>> 2.25.1
>>
-- 
Thanks,
Jiucheng